Borosilicate Glass vs. PAR
Borosilicate glass and PAR belong to fundamentally different material chemistries. Borosilicate glass is a ceramic material, while PAR is polymeric. Therefore, their performance will be even more dissimilar than would be suggested by the difference in properties. There are 17 material properties with values for both materials. Properties with values for just one material (21, in this case) are not shown.
For each property being compared, the top bar is borosilicate glass and the bottom bar is PAR.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 2000 | |
| 93 |
| Elastic (Young's, Tensile) Modulus, GPa | 67 to 80 | |
| 2.0 |
| Flexural Strength, MPa | 34 to 69 | |
| 75 |
| Tensile Strength: Ultimate (UTS), MPa | 280 | |
| 67 |
Thermal Properties
| Specific Heat Capacity, J/kg-K | 830 | |
| 1200 |
| Thermal Conductivity, W/m-K | 1.2 | |
| 0.18 |
| Thermal Expansion, µm/m-K | 3.3 to 5.1 | |
| 88 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 Hz | 4.8 to 5.5 | |
| 3.0 |
| Dielectric Strength (Breakdown Potential), kV/mm | 5.0 to 34 | |
| 16 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 9.0 to 12 | |
| 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.2 to 2.6 | |
| 1.2 |
Common Calculations
| Stiffness to Weight: Axial, points | 15 to 17 | |
| 0.93 |
| Stiffness to Weight: Bending, points | 55 to 61 | |
| 35 |
| Strength to Weight: Axial, points | 30 to 35 | |
| 16 |
| Strength to Weight: Bending, points | 36 to 43 | |
| 31 |
| Thermal Diffusivity, mm2/s | 0.54 to 0.63 | |
| 0.13 |
| Thermal Shock Resistance, points | 50 to 91 | |
| 27 |